What are secondary air pollutants primarily produced from?

Secondary air pollutants are primarily formed through chemical reactions that occur in the atmosphere involving primary pollutants. Primary pollutants are substances like carbon monoxide, sulfur dioxide, and nitrogen oxides that are directly emitted from various sources such as vehicles, industrial processes, and natural sources.

In the atmosphere, these primary pollutants can react with other atmospheric components, such as sunlight, water vapor, and oxygen, to create secondary pollutants like ozone, particulate matter, or acid rain. For example, nitrogen oxides and volatile organic compounds (VOCs) can react in the presence of sunlight to form ozone, a key secondary pollutant that contributes to smog and has various harmful effects on health and the environment.

This understanding of secondary air pollutants underscores the importance of controlling primary emissions to mitigate the formation of harmful compounds that affect air quality and public health.